One sunny, happy day in celestial Asgard, it was Thor's birthday.
He woke up as if it was any other normal day and put on his tunic and cape, then went downstairs - only to find that no one was actually down there.
He shrugged and decided to go and wake up Loki instead of looking for his mother and Odin. He happily returned upstairs to the corridor where his and Loki's rooms were.
"Brother?" He grinned, knocking on the door of Loki's chambers. There was no answer... but Loki wasn't much of a morning person anyways, so Thor just swung open the door and went in... but Loki wasn't there.
The window was open, the bed was made and everything seemed to be in order, but there was no Loki.
"Loki?" Thor asked, but hid words fell only upon his own ears. He frowned, leaving the room and closing the door.
As soon as the room fell entirely quiet again and Loki was sure that Thor was gone he touched his foot onto the floor and creeped out of the wardrobe, the door creaking slightly.
"Loki!" Thor burst back into the room, making Loki jump and almost fall.
"Ah!"
"Where were you?"
"I was, uh... looking for the tesseract?"
"...But surely you remember it's in-""Yes, of course I do. Oh, is that Odin calling me?"
"Uh, I don't hear anything...""No, no, that's definitely him!"
"But-"
"Better go see what he wants!"
Loki ran out of the room before Loki could speak another demi-godly word.
Thor decided to go outside to find someone to talk to.
The city outside the palace was quieter than it usually was in the morning and mostly empty. He wondered down to the market square where he caught sight of Sif picking out vegetables from a stall.
"Ah, Lady Sif!" Thor grinned. She gasped and quickly turned to face him, holding her hands behind her back, "You seem to be the only one I find myself in the presence of, where is everyone?"
"Uh-they... they um - oh! There's a meeting - in the temple!"
"But my Lady, it's Thursday,"
"It's a special meeting"
"...special?" Thor asked flatly. He wasn't convinced, "Is there something you want to tell me, Sif?"
"N-no," She replied nervously, "Look, I-uh... I need to go, sorry Thor!"
"Sif!"
She'd ran away by the time Thor spoke. He sighed... why was everyone acting so strangely?
Did he stink or something?
He sniffed his armpit briefly - he smelled godly as usual, so it wasn't that.
Did he look bad - no, that's just ridiculous!
So if he looked great and smelled amazing, then why was everyone running away from him?
He sighed and carried on through the market square, interested to see what this 'special meeting' was all about.
As he left the square and neared the temple, he heard a familiar voice call his name.
"Thor, my son!"
Odin had appeared, clamping his huge hand over his son's also huge shoulder. He was grinning, but the expression didn't reach his eyes (the one of them anyway).
"Father, I know I can trust an answer from you," Thor began, "Everyone seems to-"
"Oh that's terrible, Thor, I'm so sorry," Odin cut in, "But I have something very serious I need to get to... now be a good little warrior and go stay in the palace until later"
"Why would I-"
Thor, darling, this is serious! Now go home!"
Odin turned Thor around and pushed him back towards the Markey square. Thor huffed and walked away - he found himself contemplating about exactly why Odin had a panicked look in his eye...
...and suddenly, like a meteor hit his brain, Thor realised.
The Frost Giants.
Thor ran through the square and back to the palace, up the stairs, through the front doors, up to his room and he swung open his wardrobe. He grabbed Mjolnir and his armour formed around his arms and legs.
He rushed back to the temple and burst through the doors.
"Do not fear, fellow Asgardians! I have come to - wait, why's it so dark?"
There was a pause, then:
"SURPRISE!"
All the torched suddenly lit and Thor found himself surrounded by a giant circle of his family and friends. He dropped Mjolnir in shock.
"So... the Frost Giant aren't invading?"
"Uh... no, no they're not," Sif grinned, "But there is frosting! It's a surprise party!"
"Oh... uh, what for?"
"Thor!" Odin gasped, "It is the 21st day of your birth, my son!"
"...it's my birthday?"
"Yes, now shut up and have some cake!" Loki appeared, shoving a plate into his hands. Sitting on the plate was a piece of plump, moist gold and red sponge cake with silver frosting. Thor took a bite of the tempting treat baked by Loki.
"Loki, this is-om nom-amazing!" Thor chomped.
Loki pulled a small but proud smile, "I know"
So Loki, Thor, Odin, Sif and all of the other friends and family of Thor partied and devoured cake long into the night and then eventually, one by one they began to pass out.
The next morning, Thor woke in Sif's dress, Odin was in his wife's dress and all the other men woke up in dresses too. They all started arguing over who it was whilst Loki giggled in the corner. His plan had worked! Now, to upload those gorgeous pictures of lady Thor to Facebook...